U.S. patent number 7,576,996 [Application Number 11/546,470] was granted by the patent office on 2009-08-18 for telecommunications components having reduced alien crosstalk.
This patent grant is currently assigned to The Siemon Company. Invention is credited to Douglas Bond, Brian Celella, Vinicio Crudele, Daniel J. Mullin, Mark Navarra, Vito Pagliarulo, Olindo Savi.
United States Patent |
7,576,996 |
Mullin , et al. |
August 18, 2009 |
Telecommunications components having reduced alien crosstalk
Abstract
A telecommunications system comprising: a first printed circuit
board associated with a first port, the first printed circuit board
having first plated through holes for receiving first insulation
displacement contacts associated with a first connecting block and
first traces on the first printed circuit board; a second printed
circuit board associated with a second port, the second printed
circuit board having second plated through holes for receiving
second insulation displacement contacts associated with a second
connecting block and second traces on the second printed circuit
board; wherein one of the first plated through holes, second plated
through holes, first traces and second traces is positioned to
reduce alien crosstalk between the first port and the second
port.
Inventors: |
Mullin; Daniel J. (Plantsville,
CT), Celella; Brian (Southington, CT), Pagliarulo;
Vito (Bristol, CT), Navarra; Mark (Oakville, CT),
Savi; Olindo (Kensington, CT), Crudele; Vinicio
(Watertown, CT), Bond; Douglas (Thomaston, CT) |
Assignee: |
The Siemon Company (Watertown,
CT)
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Family
ID: |
37945423 |
Appl.
No.: |
11/546,470 |
Filed: |
October 11, 2006 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20070082519 A1 |
Apr 12, 2007 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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60725554 |
Oct 11, 2005 |
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Current U.S.
Class: |
361/760;
174/261 |
Current CPC
Class: |
H04M
3/18 (20130101); H04M 3/34 (20130101); H05K
1/0228 (20130101); H01R 13/6461 (20130101); H01R
13/6477 (20130101); H01R 13/518 (20130101); H05K
1/142 (20130101); H05K 3/42 (20130101); H05K
2201/10189 (20130101) |
Current International
Class: |
H05K
7/00 (20060101) |
Field of
Search: |
;361/760 ;174/261
;439/101,540,676,941 |
References Cited
[Referenced By]
U.S. Patent Documents
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6196880 |
March 2001 |
Goodrich et al. |
6350158 |
February 2002 |
Arnett et al. |
7179115 |
February 2007 |
Hashim |
7265300 |
September 2007 |
Adriaenssens et al. |
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Primary Examiner: Reichard; Dean A.
Assistant Examiner: Semenenko; Yuriy
Attorney, Agent or Firm: Cantor Colburn LLP
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. provisional patent
application Ser. No. 60/725,554, filed Oct. 11, 2005, the entire
contents of which are incorporated herein by reference.
Claims
What is claimed is:
1. A telecommunications system comprising: a first printed circuit
board associated with a first port, the first printed circuit board
having first plated through holes for receiving first insulation
displacement contacts associated with a first connecting block and
first traces on the first printed circuit board; a second printed
circuit board associated with a second port, the second printed
circuit board having second plated through holes for receiving
second insulation displacement contacts associated with a second
connecting block and second traces on the second printed circuit
board; wherein one of the first plated through holes, second plated
through holes, first traces and second traces is positioned to
reduce alien crosstalk between the first port and the second port;
wherein the first plated through holes are positioned in a first
footprint on the first printed circuit board corresponding to the
first connecting block and the second plated through holes are
positioned in a second footprint on the second printed circuit
board corresponding to the second connecting block, the first
footprint being different than the second footprint to define an
increased distance between the first plated through holes and the
second plated through holes.
2. The telecommunications system of claim l further comprising: a
third printed circuit board associated with a third port, the third
printed circuit board having third plated through holes positioned
in the first footprint for receiving third insulation displacement
contacts associated with a third connecting block; a fourth printed
circuit board associated with a fourth port, the fourth printed
circuit board having fourth plated through holes positioned in the
second footprint for receiving fourth insulation displacement
contacts associated with a fourth connecting block; the first port,
second port, third port and fourth port being arranged in
sequential order in the telecommunications system.
3. A telecommunications system comprising: a first printed circuit
board associated with a first port, the first printed circuit board
having first plated through holes for receiving first insulation
displacement contacts associated with a first connecting block and
first traces on the first printed circuit board; a second printed
circuit board associated with a second port the second printed
circuit board having second plated through holes for receiving
second insulation displacement contacts associated with a second
connecting block and second traces on the second printed circuit
board: wherein one of the first plated through holes, second plated
through holes, first traces and second traces is positioned to
reduce alien crosstalk between the first poi and the second port;
the first printed circuit board includes first jack through holes
and the second portioned circuit board includes second jack through
holes, the first jack through holes being aligned with the second
jack through holes along an axis; the first plated through holes
and the second plated through holes are positioned in a common
footprint, the first plated through holes being shifted relative to
the second plated through holes perpendicular to the axis to define
an increased distance between the first plated through holes and
the second plated through holes.
4. The telecommunications system of claim 3 further comprising: a
third printed circuit board associated with a third port, the third
printed circuit board having third plated through holes positioned
in the common footprint for receiving third insulation displacement
contacts associated with a third connecting block; a fourth printed
circuit board associated with a fourth port, the fourth printed
circuit board having fourth plated through holes positioned in the
common footprint for receiving fourth insulation displacement
contacts associated with a fourth connecting block; the third
plated through holes being shifted relative to the fourth plated
through holes perpendicular to the axis to define an increased
distance between the third plated through holes and the fourth
plated through holes; the first port, second port, third port and
fourth port being arranged in sequential order in the
telecommunications system.
5. A telecommunications system comprising: a first printed circuit
board associated with a first port, the first printed circuit board
having first plated through holes for receiving first insulation
displacement contacts associated with a first connecting block and
first traces on the first printed circuit board; a second printed
circuit board associated with a second port, the second printed
circuit board having second plated through holes for receiving
second insulation displacement contacts associated with a second
connecting block and second traces on the second printed circuit
board; wherein one of the first plated through holes, second plated
through holes, first traces and second traces is positioned to
reduce alien crosstalk between the first port and the second port;
the first traces being positioned in a first pattern and the second
traces being positioned in a second pattern, the first pattern
being different from the second pattern to reduce alien crosstalk
between the first port and the second port.
6. The telecommunications system of claim 5 further comprising: a
third printed circuit board associated with a third port, the third
printed circuit having third traces positioned in the first
pattern; a fourth printed circuit board associated with a fourth
port, the fourth printed circuit having fourth traces positioned in
the second pattern; the first port, second port, third port and
fourth port being arranged in sequential order in the
telecommunications system.
Description
BACKGROUND
The invention relates generally to telecommunications components,
and in particular to telecommunications components designed to
reduce alien crosstalk. In an electrical communication system, it
is sometimes advantageous to transmit information signals (video,
audio, data) over a pair of wires (hereinafter "wire-pair" or
"differential pair") rather than a single wire, wherein the
transmitted signal comprises the voltage difference between the
wires without regard to the absolute voltages present. Each wire in
a wire-pair is susceptible to picking up electrical noise from
sources such as lightning, automobile spark plugs and radio
stations to name but a few. Because this type of noise is common to
both wires within a pair, the differential signal is typically not
disturbed. This is a fundamental reason for having closely spaced
differential pairs.
Alien crosstalk is the differential crosstalk that occurs between
communication channels. To reduce this form of alien crosstalk,
shielded systems containing shielded twisted pairs or foiled
twisted pair configurations may be used. However, the inclusion of
shields can increase cost of the system. Another approach to reduce
or minimize alien crosstalk utilizes spatial separation of cables
within a channel and/or spatial separation between the jacks in a
channel. However, this is typically impractical because bundling of
cables and patch cords is common practice due to "real estate"
constraints and ease of wire management.
Thus, there is a need in the art for telecommunications components
that reduce or minimize alien crosstalk between communications
channels.
SUMMARY
An embodiment of the invention is a telecommunications system
comprising: a first printed circuit board associated with a first
port, the first printed circuit board having first plated through
holes for receiving first insulation displacement contacts
associated with a first connecting block and first traces on the
first printed circuit board; a second printed circuit board
associated with a second port, the second printed circuit board
having second plated through holes for receiving second insulation
displacement contacts associated with a second connecting block and
second traces on the second printed circuit board; wherein one of
the first plated through holes, second plated through holes, first
traces and second traces is positioned to reduce alien crosstalk
between the first port and the second port.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A illustrates alien crosstalk between outlets.
FIG. 1B illustrates alien crosstalk between cables.
FIG. 2 illustrates printed circuit boards as positioned in a patch
panel.
FIG. 3 illustrates alien crosstalk between printed circuit boards
of FIG. 2.
FIG. 4 illustrates a first embodiment for reducing alien crosstalk
printed circuit boards.
FIG. 5 illustrates a second embodiment for reducing alien crosstalk
printed circuit boards.
FIG. 6 illustrates alien crosstalk between printed circuit
boards.
FIG. 7 illustrates a third embodiment for reducing alien crosstalk
printed circuit boards.
FIG. 8 is a perspective view of the rear of a patch panel.
DETAILED DESCRIPTION
Embodiments of the invention provide category 6 augmented compliant
components for the new IEEE 802.3an 10GBASE-T application which is
furthered defined in the draft TIA/EIA-568-B.2-10 Augmented
category 6 draft. Connectors, cables, and patch cords meet the new
alien near end crosstalk (ANEXT) and alien far end crosstalk
(AFEXT) requirements. The alien crosstalk requirements are defined
by limits in the TIA/EIA-568-B.2-10 draft and are called powersum
alien NEXT and powersum alien equal level far end crosstalk
(ELFEXT). These limits were defined to minimize noise from one
connector or channel to another.
Market trends have shown a need for faster networks with greater
bandwidth. The Institute of Electrical and Electronics Engineers
(IEEE) has established a project team (formally known as IEEE
802.3an.TM.) to develop 10 Gigabit Ethernet that would operate over
horizontal, structured twisted pair cabling.
The IEEE project team has identified alien crosstalk to be the most
dominant noise source in the proposed channel. A channel is
comprised of cable, connectors and patch cords. The "channel" is
designed to meet minimum performance criteria to ensure its ability
to transmit the given application such as 10 Gigabit Ethernet. The
Telecommunications Industry Association (TIA) is given the task of
defining the cable, cord and connector requirements in support of
the "channel" requirements needed to guarantee 10 Gigabit Ethernet
transmissions.
Alien crosstalk is a measure of unwanted signal coupling from one
or more pairs from one channel (or more) to a neighboring adjacent
channel, expressed in decibels. FIGS. 1A and 1B show conceptual
drawings of alien crosstalk in a cluster of connectors and cables.
In FIG. 1A, outlets 10 are depicted contributing alien crosstalk to
outlet 12. The outlets 10 and 12 are connected to cables and patch
cords in a channel and are subject to alien crosstalk from the
neighboring connectors as shown. In FIG. 1B, cables 20 are depicted
contributing alien crosstalk to cable 22.
Alien crosstalk is a very difficult parameter to model due to its
random statistical nature. The affects of alien crosstalk are best
described using the powersum mathematical relationship. The
requirements specified by TIA and IEEE are in the form of Powersum
alien NEXT and Powersum alien ELFEXT as shown below: PS ANEXT.sub.k
of pair k is computed as follows:
.times..times..times..times..times..noteq..times. ##EQU00001##
where i is the number of the disturbing pair; k is the number of
the disturbed pair; n is the total number of disturbing pairs;
ANEXT.sub.ik is the alien near end crosstalk loss coupled from pair
i into pair k.
In exemplary embodiments, within each connector and through the
channel there are 4 pairs of wires. Powersum adds the noise from
the different combinations for each pair, 1 through 4. For example,
each connector has four pairs, P1, P2, P3 and P4. The noise from
each connector to the victim connector for each pair combination is
summed (P1/1, P2/1, P3/1, P4/1) for each connector that surrounds
the victim. The TIA test method calls for 6 connectors to surround
the victim cable. The affects of all pair 1 combinations are then
summed together. The worse case alien crosstalk coupling occurs
with pairs exhibiting similar twist rates. The response of the
multiple disturbers to one (of 4 possible) victim pair is summed to
obtain the mathematical powersum coupling.
The like pair responses tend to add and can cause spikes in the
data due to the powersum formula. To minimize the spikes of like
pair combinations, it is advantageous to limit the likeness of
cables and connectors in the surrounding area. This can be done in
several ways as described herein.
FIG. 2 shows a series of conventional PCBs corresponding to
adjacent ports in a patch panel, for example. The PCBs may be
similar to those described in U.S. published patent application
20040147165, the entire contents of which are incorporated herein
by reference. The PCBs in FIG. 2 have the same trace layout.
FIG. 3 illustrates a distance A between connecting block insulation
displacement contacts (IDCs) of conventional PCBs. As known in the
art, (IDCs) are electrically connected to the PCB at plated through
holes 30 and 32. The IDCs are preferably part of a connecting
block, which provides a point at which wires are terminated to the
component. As discussed herein, the IDCs in plated through holes 30
and 32 provide a location for alien crosstalk as the IDCs radiate
signals between PCBs 36 and 38. One of the major contributors to
alien crosstalk coupling between connectors comes from the
termination of the cable to the connecting block. The close
proximity and the size (height and width) of the IDCs tend to
radiate a lot of coupling signals.
Embodiments of the invention increase the distance between IDCs in
connecting blocks by offsetting the connector ports completely
(meaning the jack, PCB, and block are shifted) or by offsetting the
connecting block only. FIG. 4 shows a first embodiment in which
PCBs 42 and 44 use a two different connecting blocks resulting in
different footprints for plated through holes 46 and 48. Plated
through holes 46 and 48 receive IDCs in the connecting blocks. The
PCB used may alternate (e.g., 42, 44, 42, 44) across the ports in a
patch panel. The jack connections remain in the same location from
port to port. As shown in FIG. 4, this results in increased
distance A between connecting block IDCs 46 and 48, thus reducing
alien crosstalk.
FIG. 5 shows four adjacent port PCBs 52 and 54 using the same
connecting block design having the same footprint of plated through
holes 56 and 58. In this embodiment, the connecting block is
shifted in a first direction on port 52 and a second direction
(opposite the first direction) on port 54. The shifting of the
plated through holes for the connecting block is relative to the
jack through holes 60 on the PCBs 52 and 54. The jack through holes
footprint 60 remains in the same location from port to port aligned
on axis X. The plated through holes 56 and 58 are shifted relative
to each other in a direction perpendicular to axis X to achieve
separation. The PCB used may alternate (e.g., 52, 54, 52, 54)
across the ports in a patch panel.
By utilizing a different connecting block on the connector (as
shown in FIG. 4) or shifting the location of a common connecting
block (as FIG. 5), the distance, A, between the connecting block
IDCs of one port to the next is increased.
In many PCB embodiments, PCB traces are used to reduce crosstalk
for a given category or transmission performance. Exemplary PCB
designs are described in U.S. published patent application
20040147165. In conventional designs, each adjacent port in a patch
panel uses a PCB having the same trace layout.
FIG. 6 illustrates the alien crosstalk coupling from adjacent PCBs
62 to the "victim" PCB 64. The connectors in FIG. 6 are identical
as represented by their PCB trace layouts.
The amount of alien crosstalk is also dependent on the distance
between connectors. As the distance increases the magnitude of the
coupling fields decrease and the level of Powersum ANEXT and
Powersum alien ELFEXT also decreases. However, in instances when
space is not available, improvements can also be obtained from
eliminating similar features from adjacent ports.
FIG. 7 illustrates embodiments of the invention in which adjacent
connectors have the same jack and connecting block (not shown), but
different trace patterns on the PCB. PCB 72 has a trace pattern
that differs from that on PCB 74. Improvements in alien crosstalk
are obtained by eliminating or repositioning like/similar
compensation traces or current carrying traces, in one port design
versus the next. Port A has one PCB trace design 72 and port B has
another PCB trace design 74. The two trace patterns can be
alternated in a multi-port panel or faceplate (ABABABAB . . . B).
The differing trace patterns on the PCBS 72 and 74 reduces alien
crosstalk between the two PCBs.
FIG. 8 is a perspective view of the rear of a patch panel 80 that
utilizes PCBs 52 and 54 of FIG. 5. As shown in FIG. 8, the
connecting blocks 100 and 102 are staggered relative to each other.
This is due to the different circuit boards 52 and 54, and the
locations of the plated through holes 56 and 58 on the respective
boards. Connecting blocks 100 and 102 are the same, but shifted due
to the configuration of circuit boards 52 and 54.
Embodiments of the invention use varying PCB layouts to reduce
alien crosstalk. Exemplary designs utilize two different printed
connector designs in adjacent ports of a patch panel (or faceplate)
to eliminate similarities in adjacent designs that would couple as
noise from one connector (channel) to the adjacent connector
(channel). These designs cover a minimum of two ports but can also
be utilized in any number of ports. A connector includes a jack,
printed circuit board (PCB), and connecting block as known in the
art. A connector design can also be of the lead-frame type.
Connectors can be individually arranged in patch panels or be part
of a PCB type multi-connector design where one PCB board has
several connector ports. To reduce alien crosstalk, adjacent ports
have different electrical layouts. This difference can be
accomplished by having a different printed circuit board trace
layout in the adjacent ports or completely different components,
such as the jack, connecting block, and PCB.
Embodiments of the invention use different connectors in adjacent
ports. In a side-by-side scenario or patch panel implementation,
each connector location is designated as a "port". A two-port
implementation would then have two completely different connectors
such as a PCB type connector next to a lead frame type connector or
two different types of PCB style connectors. This could also be
done in a patch panel that uses individual connectors. Each port
would alternate connectors. For example, ports 1,3, 5 . . x would
be the same PCB type connector and ports 2,4,6 . . y would be the
lead frame type.
Patch panels can have multiple ports, such as 24, or they can be
individually inserted connectors or a finished patch panel with
connector components (connecting block and jack) mated a single PCB
with multiple jacks/blocks. In most multi-port (2 or more) printed
circuit board designs, the jack and block at each port are the same
and the PCB compensated trace layout is the same as shown in FIG.
3.
While this invention has been described with reference to a
preferred embodiment, it will be understood by those skilled in the
art that various changes may be made and equivalents may be
substituted for elements thereof without departing from the scope
of the invention. In addition, many modifications may be made to
adapt a particular situation or material to the teachings of the
invention without departing from the essential scope thereof.
Therefore, it is intended that the invention not be limited to the
particular embodiment disclosed as the best mode contemplated for
carrying out this invention.
* * * * *